1. Field of the Invention
Embodiments of the present invention relate to a flexible storage battery and a flexible electronic device.
Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. One embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a storage battery, a storage device, a method for driving any of them, and a method for manufacturing any of them.
2. Description of the Related Art
In recent years, a variety of storage batteries such as lithium-ion storage batteries, lithium-ion capacitors, air cells, and fuel cells have been actively developed. In particular, demand for lithium-ion storage batteries with high output and high energy density has rapidly grown with the development of the semiconductor industry and with the growth of demand for energy saving, for electronic devices, for example, portable information terminals such as mobile phones, smartphones, and laptop computers, portable music players, and digital cameras; medical equipment; next-generation clean energy vehicles such as hybrid electric vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid electric vehicles (PHEVs); stationary storage batteries; and the like. The lithium-ion storage batteries are essential for today's society. Furthermore, with the growing expectations for flexible devices or wearable devices in recent years, the development of lithium-ion storage batteries that have flexibility to be changed in form in accordance with a change in the form of the devices, i.e., flexible storage batteries is urgently necessary and has partly been started (Patent Document 1).
A lithium-ion storage battery, which is a nonaqueous secondary battery, includes a positive electrode, a negative electrode, a separator, a nonaqueous electrolytic solution, and an exterior body covering these components. In lithium-ion storage batteries, positive electrodes and negative electrodes are generally used; the positive electrodes each include a positive electrode current collector made of a metal such as aluminum and a positive electrode mix that includes a positive electrode active material capable of receiving and releasing lithium ions and that is applied to each surface of the positive electrode current collector, and the negative electrodes each include a negative electrode current collector made of copper or the like and a negative electrode mix that includes a negative electrode active material capable of receiving and releasing lithium ions and that is applied to each surface of the negative electrode current collector. These positive and negative electrodes are insulated from each other by a separator provided therebetween, and the positive electrode and the negative electrode are electrically connected to a positive electrode terminal and a negative electrode terminal, respectively, which are provided on the exterior body. The exterior body has a certain shape such as a cylindrical shape or a rectangular shape.